Pump.



0. 6. WELD.

PUMP.

APPLICATION FILED FEB. 28, mo.

1,1633%. Patented Dec.14,1915.

W W Z151 1.

ZZ/itnessea I COLUMBIA PLANDGRAPH co., WASHINGTON, n. c.

CARLEY G. WELD, OF NORTH CHATHAM, MASSACHUSETTS.

PUMP.

Specification of Letters Patent.

Patented Dec. 1a, 1915.

Application filed February 28, 1910. Serial No. 546,358.

To all whom it may concern:

Be it known that I, CARLEY G. WELD, a citizen of the United States, residing at North Chatham, in the county of Barnstable and State of Massachusetts, have invented new and useful Improvements in Pumps, of which the following is a specification.

This invention relates to improvements in pumps of that class which are used in combination with a suitable engine having one or more cylinders, one of which is in communication with the pump cylinder and by reason of such communication the pump pis ton is reciprocated by the alternate increase and diminution of pressure within the engine cylinder with which the pump cylinder communicates.

The pump which forms the subject'matter of my invention is particularly intended and adapted for inflating tires of motor vehicles in which case the pump cylinder is connected to one of the cylinders of the engine of the vehicle whether said engine be of the steam'type or the internal combustion type.

The object of my invention is to provide a pump of the class described which shall be simple in construction and quiet in operation, and the object is further to provide a pump so constructed that only pure air shall be pumped into the tires.

The invention consists in the noval features of construction and in the combination and arrangement of parts set forth in the following specification and particularly pointed out in the claims.

Referring to the drawing: Figure 1 is an elevation of a pump embodying my invention, the same being shown connected to an internal combustion engine. Fig. 2 is an enlarged detail sectional view of the pump taken on line 22 of Fig. 1.

In the illustration, a cylinder-casing 5, is shown, in which the body 6, is mounted to reciprocate free from restraint. The cylintier-casing is shown of two diameters. One portion 7. is of a larger diameter than is the other portion 8, thus forming two cylinders or chambers as it were, within the casing, the casing being open from end to end. In the present illustration, the two portions of the cylinder casing are made separable one from the other and are connected by means of a screw-threaded joint. The cylinder or chamber 7, will be open to some expansive force subject to variations which Will produce the reciprocation of the body 6. The body 6 is shown made up of a pair of pistons 9 and 10, connected by means of a bar or rod 11. The piston 9 is provided with suitable piston-rings 12, and the piston 10 is provided with a suitable cup-leather 13. In practice the cylinder or chamber 7 will be the expansion chamber or operating element of the pump, and the cylinder or chamber 8 will be the compression or operated chamber. The cup-leather will be located in such position that in the forward or compression movement, backflow of fluid will be prevented, but upon the return or idle movement of the piston, air may pass into the cylinder 8, past the cup-leather 13, from the openings 14, which communicate with the outside air.

The outer end of the chamber or cylinder 8 is provided with an outlet 15, communieating with a connection 16. A back-pres sure-valve 17, held on its seat by a spring 18, will be provided for the outlet 15. A suitable screw-cap 19, will hold the spring and valve in place.

In practice the pump may be secured to one of the cylinders 21, of an internal combustion engine 22, by means of a screw threaded connection 23. which has an internal-bore 20, in connection with the end of the cylinder or chamber 7.

Then it is desired to use the pump in connection with an internal combustion engine, a spark-plug will be taken from one of the cylinders and the connection 23 inserted in the place from which the spark-plug was re moved. Upon each compression stroke of this cylinder. there will be an expansion of fluid in the chamber 7. behind the piston 9, which will drive this forward and cause the piston 10 to compress the air before it and drive this through the outlet 15, and past the valve 17 Upon the reverse movement of the piston in the engine cylinder to which the pump is connected, the piston 9 will be drawn down by means of the compression of fluid thus crea ed, and will draw with it the piston 10, which. as before stated, upon its idle movement will permit air to pass from the openings 14 to the compression side of it.

It is to be observed that the cylinder as a whole is open from end to end: that the chamber 8 opens into the chamber 7, and that the member 6 is free to reciprocate within the cylinder-casing without any restraint whatsoever. It will. also be observed that the member 6 is guided by means of pack- 7 mgs of the respective pistons only. In order to prevent the pistons from striklng the ends of their respective cylinders or chambers and j thus causing an injurious and unpleasant hammering, means are provided for reducmg the area of the inlet passage and the outlet passage 15, when the piston has i and the passage 20, so that as the piston is drawn down and the projection 2i enters the passage 20, the outflow of the fluid between the piston and the cylinder-head will be restricted and a small amount of the fluid made captive so that a cushioning effect will be provided and the piston will be stopped without shock or jar. The piston 10 carries a projection located in position to enter the outlet-passage 15 at about the completion of the forward or working stroke of the piston 10. Suitable clearances will be provided between the projection and the outlet 15, so that the fluid under compression at about the completion of the compression stroke will be retarded in its outward movement and a cushion provided between the piston 10 and the cylinder-head.

There will be suflicient clearance between the projection 24: and the inlet-passage 20 to permit the incoming fluid upon the working stroke to pass into the cylinder and engage the entire working area of the piston 9.

Although but one form of this invention is illustrated and particularly described, yet it will be apparent that changes in construction may be made without departing from the spirit of the invention.

Having thus described my invention, I claim and desire to secure by Letters Patent:

1. A pump adapted to be connected to one cylinder of a multiple cylinder internal combustion engine, comprising a casing open from end to end and having an inlet and an outlet and embodying an expansion chamber and a compression chamber of lesser diameter than said expansion chamber, said expansion chamber being provided with an .inlet port located in the wall thereof, a

member mounted within said casing to reciprocate free from restraint therein and comprising a piston located in each of said chambers and means carried by each piston and adapted to cooperate with said inlet and said outlet respectively to retard the movement of said member in a plurality of predetermined directions, said pump being functioned by the compression stroke of the piston within said engine cylinder, whereby the fluid passes from said expansion chamber past the piston in said compression chamber, the fluid being compressed in said compression chamber and discharged throughsaid outlet.

'2. A pump adapted to be connected to onecylinder of a multiple cylinder internal combustion engine comprising a casing embodying two portions normally connected for disasse'mblage one from the other, one

of said portions providing an expansion chamber and the other of said portions forming a compression chamber of lesser diameter than. said expansion chamber, said casing being open from end to end and a member mounted within said casing to reciprocate free from restraint therein and comprising a piston located in each of said' chambers, the piston in said compression chamber having a cup washer mounted thereon, said pump being functioned by the operation of the piston within said engine cylinder whereby the fluid flows from said expansion'chamber past said compression piston into said compression chamber.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

y CARLEY G. VVELDJ Witnesses GEORGE H. ADAMS, CHARLES H. OLSON.

Copies of this patent may be obtained for five cents each. by addressing the Commissioner of Patents,

Washington, D. G. 

